Wednesday, March 19, 2014

The Seattle Building Boom

A Seattle city block is 236' X 240' this building is 1/2 block. They are moving a lot of dirt by way of heavy machinery, a big conveyor belt and a lot of dump trucks. Where does all that dirt GO?

A common site are these truck-trailer combinations all over the city hauling all that excavated dirt somewhere?

It takes less than 2 minutes to load that trailer full.

The conveyor is extended as the hole gets deeper

I am wondering how will they get all that heavy machinery out of there once the hole is complete?

These Steel I Beams are pile driven every 12' around the entire perimeter of the building

Here you can see the row of I beams driven over 5 stories into the ground. How do they drive them so Vertically Level and so straight in line?

Huge 6X8 wood beams are slid into the channels between the I beams forming a wall downward. All of this is anchored to the earthen sides by long anchors driven into the sidewalls at regular intervals. 

The hole is nearing completion as the first concrete has been poured in the center and the first leg of the construction crane is in place (the yellow object just the other side of the conveyor belt.

A little detail excavation left to do. After a long day in the hole those guys have a considerable stair climb to end their day.

I hope I get to see them install the crane.

They have to get all these huge excavators out somehow?

I wonder if this crane can lift them out>

I got lucky as I got to see the finishinig touches to installing the construction crane. 1st they have a small crane build the big mobile crane. Then the big mobile crane lifts the pieces to build the yellow construction crane. 

One of the workman tells me that this big mobile crane will be used to lift out all the heavy excavating equipment as well.

That big mobile crane is pretty incredible reaching way up there.

The little crane unloads the pieces for the big crane.

Those guys up there have to have a lot of trust in the operator of the big mobile crane. Watch out Below!

Just a acouple of more pieces left to install on the boom, imagine walking out to the edge to install the pins and bolts.
A few weeks later I was walking by and noticed these pre cut cables down in the hole.

And then I realized they were using Post Tensioned Systems cable for their concrete reinforcement. Back in my 20's I worked for a Post systems company in Arlington Texas and was a Tech that came along with a hydraulic ram and tensioned the cables. This is used rather than the standard steel Re-Bar.
Here you can see the concrete has been poured, after it cures for several days then the cable ends you see sticking out in the slot in the center of the pic will be tensioned.
5-11-14 Update to the picture above as the structure nears street level 
5-27-14 update to the picture above as the building has reached street level A story in the Seattle Times said all the new condo buildings going up were already mostly  pre leased or purchased  so they would not effect rents. Some apartment buildings are being converted into Condos for sale.

This building is about 4 blocks from us and just had the street level floor finished when we moved here back in August. They recently removed the construction crane and have all the exterior windows installed and "Dried IN"

The Seattle Building Boom

If there are any remnants of the 2011 Financial Crises you can't tell it here in Seattle. I counted over 13 construction cranes just on my walk from Belltown to the Center of Wooden Boats in South Lake Union and the news is that construction double  in 2014. I am already seeing evidence of that as a lot of new holes are being dug all around the city. Some of these buildings are 1/4 of a city block, most I see are 1/2 of a city block and some are one or even two entire city blocks. Since they dig the holes 4-5 blocks underground that is a whole lot of dirt to move somewhere else. Since I have never lived in a downtown environment before witnessing all this highrise construction is new to me. To see how these high rise buildings evolve over time every day is fascinating to me.
I worked concrete construction for about 6 years in my early twenties, mostly big apartment buildings, warehouses, and other single story commercial buildings.  I really enjoyed construction as it was a creative job, it keeps you in really good physical shape without ever needing a gym, and there is just a sense of satisfaction at the end of every day that is highly visible. Everyday you have new problems to solve and sometimes you have to go to other contractors on the jobsite to work out a solution so you learn a bit about their piece of the construct. We used a tractor/front end loader with a box scraper, a Ditchwitch. and a Bobcat for most of our work but occasionally we had to borrow a piece of heavy machinery from the excavators to do a bit of dirt work and I always enjoyed operating all of that equipment.
One thing that has to go into these huge buildings are protections against earthquakes. They put a lot of steel in their concrete foundations. I am just hoping that the building we are living in was built  like the ones I am seeing. The recent earthquake in the news in LA makes one think, especially since we are living on the top/12th floor!

The real question I have is where does all that dirt go? Most of the pics above are from a project in South Lake Union and by my math I estimate that they had to haul out 63,200 cubic yards of dirt from that 1/2 city block sized building with a hole 5 stories deep. Those tandem dump trucks can haul 20 cubic yards at a time so it took 2,160 tandem trucks to haul it all out. Where does it all go especially considering there are dozens of job sites like this around the city??? I found this Blog about that exact topic: 
One thing I know from learning a bit about the history of Seattle is that the industry that grew in Seattle needed some flat land so they achieved that by taking the tops off of some of the foot hills in the area and created flatland to build on. The Port of Seattle is on Harbor Island, the largest man made island in the US. My guess is that they are still creating flatland!
Seattle, the city that the Mountains, forest and the Sea built!

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